Historically, super regenerative receivers have been utilized in amplitude modulated (AM) radio repeaters. Conventional super regenerative receivers are utilized with low cost, low power output transmitters. These transmitters are Federal Communication Commission (FCC) Part 15 transmitters which have such a low power output as to not require licensing. Since these transmitters are of an extremely low cost, they do not have a crystal oscillator or other frequency fixing device which would transmit with accuracy fixed frequency signals. These transmitters characteristically exhibit "frequency drifting"normally within a select frequency bandwidth. Therefore, the super regenerative receivers are able to receive a transmitted radio frequency signal within a particular bandwidth, and thereby inherently compensate for transmitter drift.
Super regenerative receivers are inherently wide band at the particular transmitted frequency which is disadvantageous in that it allows a similar bandwidth of noise to be received along with the preferred signal.
Utilizing a super regenerative receiver presents the problems of discriminating the reception of noise from preferred signals, the scrambling and loss of reception of simultaneously transmitted multiple signals, as well as compensating for the drift in transmitting frequencies and yet allowing one to receive proper RF signals. A problem is also presented in improving and designing electronic circuitry which would eliminate the above problems, and yet be cost effective in terms of design, manufacturing, and production.
It is therefore highly desirable to provide an improved hybrid electronic radio repeater which is a narrow band receiver greatly improving the signal-to-noise ratio of received signals from transmitters operating at a great distance from the receiver, and by its narrow band characteristic allows reception of simultaneously transmitted signals.
It is also highly desirable to provide an improved hybrid electronic radio repeater which greatly improves the reception of transmitted RF signals from low power output transmitters which do not require FCC licensing, and yet allows for low cost electronic components to be utilized in said receiver.
It is also highly desirable to provide an improved hybrid electronic radio repeater which maximizes the signal-to-noise ratio of received RF signals, and operates as a narrow band receiver.
It is also highly desirable to provide an improved hybrid electronic radio repeater which has an intelligent, digital processing system capable of discerning specific information data and generating specific responses thereto.
It is also highly desirable to provide an improved hybrid electronic radio repeater which can scan a select frequency band searching for preferred RF signals, and having the ability to automatically tune said radio repeater to frequency locations which optimize reception.
It is also highly desirable to provide an improved hybrid electronic radio repeater containing a digital processing unit which can initiate the transmission of data in response to received RF data, whether the transmission is a simulated transmission of the originally received signals, or a transmission of discrete, original data in response thereto.
It is also highly desirable to provide an improved hybrid electronic radio repeater which is cost effective yet operationally efficient.
It is also highly desirable to provide an improved hybrid electronic radio repeater having drift alarm zones which can alert an operator that a transmitter frequency is drifting beyond acceptable limits, as well as alert an operator as to other operational deficiencies in either the power of or distance to the transmitting source, or the operation of the repeater receiver itself.
It is also highly desirable to provide an improved hybrid electronic radio repeater which contains a digital processing system which can be utilized to scan a select frequency bandwidth searching for select RF signals, and upon sensing the presence of such RF signals initiate the fine tuning of said receiver to lock very accurately onto said select RF signals and thereby improve reception.
It is also highly desirable to provide an improved hybrid electronic radio repeater which can intelligently discriminate between varying RF signals and the transmitted data therein, and initiate ancillary support equipment in response to the transmitted data.
Finally, it is highly desirable to provide an improved hybrid electronic radio repeater having all of the above mentioned characteristics.